A : Salts of organic acids Katsarosite is a rarely occurring mineral from the mineral class of organic compounds with the chemical composition Zn(C2O4)·2H2O and is therefore a water-containing zinc(II) oxalate or the zinc salt of oxalic acid.

The color depends on the iron (Fe2+) content, ranging from pure white to yellow in Fe-rich specimens.

[2] The mineral is named after Īraklīs Katsaros (ΗΡΑΚΛΗΣ ΚΑΤΣΑΡΟΣ) of Lavrion who has led as guide a large number of scientific archaeological and mineralogical sampling tours through the ancient mining system of Lavrion.

His assistance is further acknowledged in dozens of peer-reviewed scientific papers.

[1] Type material is deposited in the collections of the Institut für Mineralogie und Kristallographie der Universität Wien, Althanstrasse 14, 1090 Vienna, Austria, catalogue number HS13.977 (holotype); the Mineralogical Museum of Lavrio, Andrea Kordella Ave., 19500 Lavrio, Greece, catalogue number T3201 (cotype)[1].